To iterate over code points, use a loop like this: *
* UnicodeSetIterator it(set);
* while (set.next()) {
* if (set.isString()) {
* processString(set.getString());
* } else {
* processCodepoint(set.getCodepoint());
* }
* }
*
*
* To iterate over code point ranges, use a loop like this: *
* UnicodeSetIterator it(set);
* while (set.nextRange()) {
* if (set.isString()) {
* processString(set.getString());
* } else {
* processCodepointRange(set.getCodepoint(), set.getCodepointEnd());
* }
* }
*
* @author M. Davis
* @draft ICU 2.2
*/
class U_COMMON_API UnicodeSetIterator : public UObject {
protected:
/**
* Value of codepoint if the iterator points to a string.
* If codepoint == IS_STRING, then examine
* string for the current iteration result.
*/
enum { IS_STRING = -1 };
/**
* Current code point, or the special value IS_STRING, if
* the iterator points to a string.
*/
UChar32 codepoint;
/**
* When iterating over ranges using nextRange(),
* codepointEnd contains the inclusive end of the
* iteration range, if codepoint != IS_STRING. If
* iterating over code points using next(), or if
* codepoint == IS_STRING, then the value of
* codepointEnd is undefined.
*/
UChar32 codepointEnd;
/**
* If codepoint == IS_STRING, then string points
* to the current string. If codepoint != IS_STRING, the
* value of string is undefined.
*/
const UnicodeString* string;
public:
/**
* Create an iterator over the given set. The iterator is valid
* only so long as set is valid.
* @param set set to iterate over
*/
UnicodeSetIterator(const UnicodeSet& set);
/**
* Create an iterator over nothing. next() and
* nextRange() return false. This is a convenience
* constructor allowing the target to be set later.
*/
UnicodeSetIterator();
/**
* Destructor.
*/
virtual ~UnicodeSetIterator();
/**
* Returns true if the current element is a string. If so, the
* caller can retrieve it with getString(). If this
* method returns false, the current element is a code point or
* code point range, depending on whether next() or
* nextRange() was called, and the caller can retrieve it
* with getCodepoint() and, for a range,
* getCodepointEnd().
*/
inline UBool isString() const;
/**
* Returns the current code point, if isString() returned
* false. Otherwise returns an undefined result.
*/
inline UChar32 getCodepoint() const;
/**
* Returns the end of the current code point range, if
* isString() returned false and nextRange() was
* called. Otherwise returns an undefined result.
*/
inline UChar32 getCodepointEnd() const;
/**
* Returns the current string, if isString() returned
* true. Otherwise returns an undefined result.
*/
inline const UnicodeString& getString() const;
/**
* Returns the next element in the set, either a single code point
* or a string. If there are no more elements in the set, return
* false. If codepoint == IS_STRING, the value is a
* string in the string field. Otherwise the value is a
* single code point in the codepoint field.
*
* The order of iteration is all code points in sorted order, * followed by all strings sorted order. codepointEnd is * undefined after calling this method. string is * undefined unless codepoint == IS_STRING. Do not mix * calls to next() and nextRange() without * calling reset() between them. The results of doing so * are undefined. * * @return true if there was another element in the set and this * object contains the element. */ UBool next(); /** * Returns the next element in the set, either a code point range * or a string. If there are no more elements in the set, return * false. If codepoint == IS_STRING, the value is a * string in the string field. Otherwise the value is a * range of one or more code points from codepoint to * codepointeEnd inclusive. * *
The order of iteration is all code points ranges in sorted * order, followed by all strings sorted order. Ranges are * disjoint and non-contiguous. string is undefined * unless codepoint == IS_STRING. Do not mix calls to * next() and nextRange() without calling * reset() between them. The results of doing so are * undefined. * * @return true if there was another element in the set and this * object contains the element. */ UBool nextRange(); /** * Sets this iterator to visit the elements of the given set and * resets it to the start of that set. The iterator is valid only * so long as set is valid. * @param set the set to iterate over. */ void reset(const UnicodeSet& set); /** * Resets this iterator to the start of the set. */ void reset(); /** * ICU "poor man's RTTI", returns a UClassID for the actual class. * * @draft ICU 2.2 */ virtual inline UClassID getDynamicClassID() const { return getStaticClassID(); } /** * ICU "poor man's RTTI", returns a UClassID for this class. * * @draft ICU 2.2 */ static inline UClassID getStaticClassID() { return (UClassID)&fgClassID; } // ======================= PRIVATES =========================== protected: // endElement and nextElements are really UChar32's, but we keep // them as signed int32_t's so we can do comparisons with // endElement set to -1. Leave them as int32_t's. const UnicodeSet* set; int32_t endRange; int32_t range; int32_t endElement; int32_t nextElement; //UBool abbreviated; int32_t nextString; int32_t stringCount; UnicodeSetIterator(const UnicodeSetIterator&); // disallow UnicodeSetIterator& operator=(const UnicodeSetIterator&); // disallow virtual void loadRange(int32_t range); private: /** * The address of this static class variable serves as this class's ID * for ICU "poor man's RTTI". */ static const char fgClassID; }; inline UBool UnicodeSetIterator::isString() const { return codepoint == (UChar32)IS_STRING; } inline UChar32 UnicodeSetIterator::getCodepoint() const { return codepoint; } inline UChar32 UnicodeSetIterator::getCodepointEnd() const { return codepointEnd; } inline const UnicodeString& UnicodeSetIterator::getString() const { return *string; } U_NAMESPACE_END #endif